Abstract

INTRODUCTION

A recurring surprise in the progress of the Upper Devonian studies has been the repeated discovery, after a piece of work had resulted in some apparently new stratigraphic correlation, that another worker, years before, had seen and recorded the same phenomenon. Thus, when the “Pocono”-“Catskill” lateral intergradation around Lock Haven, Pennsylvania, had become evident to J. L. Rich and the writer, a random reading of Chance's report on this area revealed his similar, and long prior, observation. The Wellsburg-Montrose transformation in crossing the Bradford-Susquehanna County line in Pennsylvania was also specifically noted by Andrew Sherwood, as were many like transitions in that general area, but all, apparently, like Chance's discovery, were soon relegated to limbo. They conflicted too annoyingly with established theory and nomenclature.

So perhaps it should not have surprised one after all, to find both that no less a paleontologist than John M. Clarke himself had long . . .